The UN has now published a list of countries that have met its monitoring requirements by introducing national certification schemes that make legal trade in diamonds transparent and secure.

The countries' presence on the UN list means they will be allowed to trade in diamonds under the scheme, while countries which have not met the UN requirements will be excluded.

No guarantee

But pressure groups opposed to the trade have questioned the effectiveness of the UN list.

We already have laws against theft and human rights abuse... these have not stopped conflict diamonds in the past

Ian Smillie, Partnership Africa Canada

"We are a long way away from assuring that countries are not trading in conflict diamonds," Corinna Gilfillan from Global Witness, a non-governmental organisation which has been campaigning on this issue, told BBC World Business Report.